Reference page — cumulative record through Monday, October 19, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.

CVE-2018-1061

CVE-2018-1061HIGH

[UNKNOWN] python — python before versions 2.7.15, 3.4.9, 3.5.6rc1, 3.6.5rc1 and 3.7.0 is vulnerable to catastrophic backtracking in the difflib.IS_LINE_JUNK…

  AV  AC  PR  UI  S  C  I  A   CVSS    EPSS   %ile   KEV
   N   L   N   N  U  N  N  H    7.5   .0492   92.0     —

AFFECTED
  Product  Versions         Fixed
  python   python 2.7.15 –  —

TIMELINE
  Dec 4   Reserved by redhat
  Jun 19  Published (CNA: redhat)
  Oct 15  RESCORED — CVE-2018-1061 ([UNKNOWN] python). CVSS 6.5 → 7.5 (NVD).

CWE-20 · CNA: redhat · CVSS v3.0 · 21 references · NVD status: Modified

Description

python before versions 2.7.15, 3.4.9, 3.5.6rc1, 3.6.5rc1 and 3.7.0 is vulnerable to catastrophic backtracking in the difflib.IS_LINE_JUNK method. An attacker could use this flaw to cause denial of service.

Lifecycle

Complete event history — 3 events, chronological
Date	Event	Detail
December 4, 2017	Reserved	Reserved by redhat
June 19, 2018	Published	Published (CNA: redhat)
October 15, 2026	RESCORED	RESCORED — CVE-2018-1061 ([UNKNOWN] python). CVSS 6.5 → 7.5 (NVD).

Affected

Affected products and packages — 1 row
Vendor	Product / Package	Ecosystem	Version introduced	Fixed
[UNKNOWN]	python	—	python 2.7.15	—

Weaknesses

CWE-20

References (21)

http://lists.opensuse.org/opensuse-security-announce/2020-01/msg00040.html
http://www.securitytracker.com/id/1042001 [Third Party Advisory, VDB Entry]
https://access.redhat.com/errata/RHBA-2019:0327 [Third Party Advisory]
https://access.redhat.com/errata/RHSA-2018:3041 [Third Party Advisory]
https://access.redhat.com/errata/RHSA-2018:3505 [Third Party Advisory]
https://access.redhat.com/errata/RHSA-2019:1260
https://access.redhat.com/errata/RHSA-2019:3725
https://bugs.python.org/issue32981 [Vendor Advisory]
https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2018-1061 [Issue Tracking]
https://docs.python.org/3.5/whatsnew/changelog.html#python-3-5-6-release-candidate-1 [Vendor Advisory]
https://docs.python.org/3.6/whatsnew/changelog.html#python-3-6-5-release-candidate-1 [Vendor Advisory]
https://lists.debian.org/debian-lts-announce/2018/09/msg00030.html [Mailing List, Third Party Advisory]
https://lists.debian.org/debian-lts-announce/2018/09/msg00031.html [Mailing List, Third Party Advisory]
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/46PVWY5LFP4BRPG3BVQ5QEEFYBVEXHCK/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/AEZ5IQT7OF7Q2NCGIVABOWYGKO7YU3NJ/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JSKPGPZQNTAULHW4UH63KGOOUIDE4RRB/
https://support.hpe.com/hpsc/doc/public/display?docLocale=en_US&docId=emr_na-hpesbst03951en_us
https://usn.ubuntu.com/3817-1/ [Third Party Advisory]
https://usn.ubuntu.com/3817-2/ [Third Party Advisory]
https://www.debian.org/security/2018/dsa-4306 [Third Party Advisory]
https://www.debian.org/security/2018/dsa-4307 [Third Party Advisory]

Authoritative record: CVE-2018-1061 at cve.org

Vendors: [unknown]

Weaknesses: CWE-20

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2018-1061 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Monday, October 19, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.